Your spectator selects a card for you and a card for themselves. Both are lost in the deck.

You
offer to find your card and after a shuffle or two you dramatically
turn over the top card of the deck. IT'S WRONG - it's not your selection
(or even their selection!).

Embarrassed you take it and put it
inside the empty card case. Then cleanly, and in full view you open the
card case and slide out a single playing card. IT'S YOUR SELECTED CARD!
You have miraculously changed the random card into your own selection.

You
slide it back into the box and then reach into your pocket to reveal
that a card has jumped into your pocket. Sliding it out you flip it face
up to show... YOUR SELECTED CARD?!? Wasn't that in the card case?

The card case is opened and ONE CARD is seen inside. It's the SPECTATOR'S SELECTION!!!

Special gimmick supplied. Incredibly easy to do. Instant reset.

APERTURE

A card is selected and lost in the deck.

You
then reach into your pocket and remove a Joker with a hole cut in it
and slide it halfway into the pack. The spectator pulls the Joker back
out to discover that the hole has healed!!

The deck is spread and the selection is found WITH A HOLE IN IT! THE HOLE HAS JUMPED FROM THE JOKER TO THE SELECTION.

Expressing
concern that this selected card is now useless (it's got a HOLE in
it!!), you shake it a little and before the spectators very eyes the
hole jumps back to the Joker. Everything can be handed out for
examination!